Yǒngjiā Xuánjué 永嘉玄覺 (665–713), hào Míngdào 明道, shì Zhēnjué dàshī 真覺大師, colloquially called Yīsù jué 一宿覺 (“One-Night Awakening”); a Táng Chán master, dharma-heir of Huìnéng 惠能, and author of the Zhèng dào gē 證道歌 and the Chánzōng Yǒngjiā jí (KR6q0089, T48 n2013). Native of Yǒngjiā 永嘉 (modern Wēnzhōu 溫州, Zhèjiāng), lay surname Dài 戴.
Entered monastic life at age eight. Early doctrinal training in the Three Baskets (sānzàng 三藏) and particularly in the Tiāntái 天台 zhǐguān 止觀 meditation-and-contemplation tradition, under Huìwēi 慧威 (DILA A009596) at Zuǒxī 左溪 — a Tiāntái grand-disciple of Zhìyǐ 智顗. The turning point of his career was the encounter with Huìnéng at Cáoxī 曹溪: stimulated by his fellow-student Xuáncè 玄策 of Dōngyáng, Xuánjué travelled south to interview Huìnéng; after a single night’s conversation Huìnéng acknowledged his attainment and sealed him as a dharma-heir — hence the epithet Yīsù jué. Returned to Yǒngjiā, held an abbacy, gathered students, and died on Xiāntiān 2.10.17 (13 November 713), aged 49; buried at the Lóngxīng sì 龍興寺 in Wēnzhōu.
Xuánjué’s doctrinal signature is his synthesis of Tiāntái zhǐguān practice with Huìnéng-lineage Chán, most fully articulated in the ten-essay Chánzōng Yǒngjiā jí. The Zhèng dào gē 證道歌 (“Song of Awakening-Verification”) — a short rhymed didactic poem in seven-character lines, independent text, not included in KR6q0089 — is his best-known work and forms, with Sēngcàn’s Xìn xīn míng 信心銘 (KR6q0085), the canonical short-verse pair of early Chán didactic poetry.
Named dharma-heirs (DILA): Huìcāo 惠操 (A010132), Huìtè 惠特 (A010133), Děngcí 等慈, Xuánjì 玄寂.
Works in the Kanripo corpus: KR6q0089 Chánzōng Yǒngjiā jí 禪宗永嘉集 (1 juan, T48 n2013), compiled posthumously by the Táng cìshǐ of Qìngzhōu 慶州, Wèi Jìng 魏靜, from ten essays Xuánjué had composed during his lifetime.
Per DILA A010119: birth 665 (sui reckoning from 49-year lifespan ending in 713); death Xiāntiān 2.10.17 (13 November 713); native of Yǒngjiā.